Mixing system having non-contacting bearings

Abstract

A seal-less immersible mixing system for agitating materials contained within a storage tank. The mixing system utilizes an induction motor to drive a drive shaft having an impeller. The mixing system also includes a plurality of magnetic non-contact bearings circumferentially located around a portion of the drive shaft. The magnetic bearings reduce periodic service requirements typically required of existing mixing systems using contact bearings. Elimination of mechanical seals further reduces periodic service requirements of existing mixing systems utilizing mechanical seals.

What is claimed is:  
     
         1 . A mixing system for agitating materials contained in a storage container, the mixing system comprising: 
 a drive shaft having an impeller;    a casing covering a portion of a length of said drive shaft;    a plurality of non-contact bearings circumferentially located around a portion of said drive shaft within said casing, said plurality of non-contact bearings supporting said drive shaft within said casing; and    means for rotating said drive shaft, rotation of said drive shaft causing movement of the impeller for agitating materials contained in the storage container.    
     
     
         2 . The mixing system for agitating materials of  claim 1  wherein the means for rotating said drive shaft is an induction motor.  
     
     
         3 . The mixing system for agitating materials of  claim 2  wherein the induction motor includes a rotor and induction coils surrounding a portion of said drive shaft.  
     
     
         4 . The mixing system for agitating materials of  claim 1  wherein the plurality of non-contact bearings are magnetic bearings.  
     
     
         5 . The mixing system for agitating materials of  claim 1  wherein said drive shaft, said plurality of non-contact bearings, and the impeller are coated with a substance impervious to the materials being agitated.  
     
     
         6 . The mixing system for agitating materials of  claim 1  wherein said mixing system is immersed within the materials being agitated.  
     
     
         7 . A mixing system for agitating materials, the mixing system comprising: 
 a storage container holding a liquid in an interior portion of said storage container;    a drive shaft having an agitating means, said drive shaft being positioned within the interior portion of said storage container;    a casing covering a portion of a length of said drive shaft;    a plurality of non-contact bearings located around a portion of said drive shaft within said casing, said plurality of non-contact bearings aligning said drive shaft within said casing; and    means for rotating said drive shaft, rotation of said drive shaft causing the agitating means to agitate the liquid held in the interior portion of said storage container.    
     
     
         8 . The mixing system for agitating materials of  claim 7  wherein said agitating means is an impeller.  
     
     
         9 . The mixing system for agitating materials of  claim 7  wherein the means for rotating said drive shaft is an induction motor.  
     
     
         10 . The mixing system for agitating materials of  claim 9  wherein the induction motor includes a rotor and induction coils surround a portion of said drive shaft.  
     
     
         11 . The mixing system for agitating materials of  claim 7  wherein the plurality of non-contact bearings are magnetic bearings.  
     
     
         12 . A mixing system for agitating materials, the mixing system comprising: 
 a storage container holding a liquid in an interior portion of said storage container;    a drive shaft having an impeller, said drive shaft being positioned within the interior portion of said storage container;    a casing covering a portion of a length of said drive shaft;    a plurality of non-contact magnetic bearings circumferentially located around a portion of said drive shaft within said casing, said plurality of non-contact bearings positioning said drive shaft within said casing; and    an induction motor having a rotor and induction coils surrounding a portion of said drive shaft for rotating said drive shaft, rotation of said drive shaft causing the impeller to agitate the liquid held in the interior portion of said storage container.